When a command terminates on a fatal signal, bash uses the value of 128+signal as the exit status. Institutions that rely solely on commercial-proprietary vendors - whether on-premises or cloud-based - effectively outsource their IT strategy and reduce their capability to deal with change with agility. Specific filesystems, however, may impose …

It would not be enough to stop here, though. The world economy will not collapse if creators of software choose to share their work with the world. It may not be the best choice for word processing (or maybe it is -- read on), but many see it as an "ISP …

Over the years, Unix systems have supported a handful of different special files. Like so many others I have always thought that one of the greatest attributes of Linux is its diversity of choice, but there are those outside of the Linux world that see this as a negative. Quite …

Where Linux has shown a significant advantage over proprietary Unix is in its availability across a vast number of hardware platforms and devices. Another type of open source license is the artistic license, which ensures that the source code of the program is freely available yet allows the original author …

The receiving IP layer uses that protocol identifier to decide which layer to pass the received data up to, in this case the TCP layer. Kernel modules, like the kernel itself, are usually written in C. When Linux fixes up that page fault it finds the vm_area_struct data structure describing …

You may have already noticed that in order to execute shell script the file needs to be made executable by use of chmod +x FILENAME command. The kernel calls the modules initialization routine and, if it is successful it carries on installing the module. The g++ C++ compiler is ISO …

Many times, it does this in order to avoid vice, but counterintuitively, only ends up creating more of it in the process. At kernel initialization time, the address families built into the kernel register themselves with the BSD socket interface. This subshell reinitializes itself, so that the effect is as …

This is especially true for large contributions, new features, or standalone code, like a driver for a specific piece of hardware. Knowledge and information are the building blocks of change. A runnable process is one which is waiting only for a CPU to run on. In addition, in the open …

Binary compatibility is maintained across a given major version of glibc, at the very least. Does it support my critical applications? Linux aims toward POSIX and SUS compliance. Of course, most system calls have only a couple of parameters.

Getting Enlightenment to work with a dual screen monitor

When a command terminates on a fatal signal, bash uses the value of 128+signal as the exit status. Let's look at creating an image file so we can start a container which we created. Much of enterprise IT's excitement is focused on advancements at the application level (and rightly …

Some operating systems, such as VMS, provide highly structured files, supporting concepts such as records. Linux maintains the set of registered block devices as the blkdevs vector. A process is also associated with various system resources, which are arbitrated and managed by the kernel. Its own Software Center has tons …

So when you're writing something in your word processor and you want to check out something on the web, no need to review all your windows to find your browser, stacked all the way behind the others. If you are not already familiar with the GNU GPL, the best way …

Richard Stallman's stallman.org is a perfect example. This behaviour has spawned a whole new wave of viruses and is a gross breach of privacy. It will recognize a multiline header if the last character on each line but the last is a left parenthesis or comma. Much of enterprise …

For high speed devices, such as hard disk controllers or ethernet devices the data transfer rate is a lot higher. Even in the days before the Internet, information and so-called "intellectual property" could still be, and were, exchanged. The proto_ops data structure consists of the address family type and a …

This allows the ethernet layer to correctly receive IP packets and to pass them onto the IP layer. The boot disks are located in the bootdisks/ directory in the distribution tree. Indeed, they even have associated inodes. It is vital that we keep a philosophical approach so that our beliefs …

The first thing I do when I get a new computer is format my drive and install Linux. There are many ways to make money, so why choose a method that requires investing just as much time and effort into making software that lots of people want to use as …

Dynamically loading code as it is needed is attractive as it keeps the kernel size to a minimum and makes the kernel very flexible. For DOS formatted disks, those formatted by fdisk, there are four primary disk partitions. Linux is that power. The originator of the request, the client, creates …

The kernel allocates a new module data structure and enough kernel memory to hold the new module and puts it at the end of the kernel modules list. By virtue of its open source licensing, Linux is freely available to anyone. People who develop OSS commonly use the Internet to …

You can easily see the exported kernel symbols and their values by looking at /proc/ksyms or by using the ksyms utility. As the writing process writes to the pipe, bytes are copied into the shared data page and when the reading process reads from the pipe, bytes are copied …

This is one of those arguments that sounds good superficially but which is not borne out by the evidence. If the thief runs, he/she probably won't get caught, and it is a quick way to make some extra cash. If you've always wanted to learn programming, whether you want …

These negative connotations include lack of quality, of robustness, of support and of long-term commitment. The shell program is what presents the prompt and accepts subsequent commands. This means that it's not enough for a Linux platform to support what an enterprise needs right now. Copyright does not protect facts …

IP addresses on the other hand can be assigned and reassigned by network administrators at will but the network hardware responds only to ethernet frames with its own physical address or to special multicast addresses which all machines must receive. Any site that is requested through the "what's that site …

Device drivers have to be careful when using DMA. Let's face it; Windows OS is vulnerable to different types of attacks (or hacks). However, the root user is the only one who is able to add new users to the system. For self study it can be useful to have …

Institutions that rely solely on commercial-proprietary vendors - whether on-premises or cloud-based - effectively outsource their IT strategy and reduce their capability to deal with change with agility. This greatly assists integration efforts - and facilitates movement between systems when necessary. But, due to some recent changes, Ubuntu has switched back to GNOME …

All Unix versions and workalikes, including Linux, communciate between devices (computers, printers, cash registers, etc) using TCP/IP. Where Linux has shown a significant advantage over proprietary Unix is in its availability across a vast number of hardware platforms and devices. As both communities have matured over the past decade …

When a user-space application requests that a given filename be opened, the kernel opens the directory containing the filename and searches for the given name. If the expiry time for an active timer has expired (expiry time is less than the current system jiffies), its timer routine is called and …

A mechanism is needed whereby activities can be scheduled to run at some relatively precise time. The registered protocol operations are kept in the pops vector, a vector of pointers to proto_ops data structures. This showcased not only how the Linux community works together to handle critical software security threats …

The device driver places bytes onto the queue, one by one, and user space reads the bytes in the order that they were placed on the queue. Although Linux was only created in 1991, the number of Linux users estimated by Red Hat in 1998 was 7.5 million, and …

Linux runs faster than both Windows 8.1 and Windows 10 thanks to its light-weight architecture. Common feedback would include questions about how something works or why you chose a particular approach along with suggestions for improvements or requests for changes. A block device cannot transfer or access a unit …

The saved uid stores the original effective uid; its value is used in deciding what effective uid values the user may switch to. The installation and setup process of this Linux distro for programmers is almost just like Fedora. The address bus specifies the memory locations (addresses) for the data …

The read/write heads are moved across the surface of the platters by an actuator. The BSD socket layer passes the socket data structure representing the BSD socket to the INET layer in each of these operations. An operating system needs to be able to schedule an activity sometime in …

These common interfaces mean that the kernel can treat often very different devices and their device drivers absolutely the same. In order to be accessed, a file must first be opened. It has the same rights and responsibilities as any kernel code; in other words, Linux kernel modules can crash …

Compare this to a floppy disk which only spins at 360 RPM. In fact, it seemed so obvious that the situation with regard to software resembled that of mathematics or recipes that terminology such as free software, freeware and open source software did not exist for many years. The terminal …

Closed source software can be distributed for free or for a cost; either way, the source code for the software is unavailable from the original developers. In Linux, no further organization or formatting is specified for a file. Until Linux came along it was either Windows or Macintosh - take it …

Approaching open source contributions without a strategy can tarnish a company's reputation in the open source community and incur legal risks. If the program is a file beginning with #!, the remainder of the first line specifies an interpreter for the program. What happens if you load a module built for …

The price for a Windows license amounts to an average of one fourth of each new computer's price. Many of the devices you own probably, such as Android phones, digital storage devices, personal video recorders, cameras, wearables, and more, also run Linux. Linux systems always have a root filesystem. Again …

With respect to language standards, Linux fares well. Note that Windows NT systems cannot be included in this survey (because their uptimes couldn't be counted). 99 in Windows). The minor device numbers are used to distinguish between different devices and their controllers, for example each partition on the primary IDE …

The new vm_area_struct structure is put into the list of vm_area_struct pointed at by the shmid_ds. Internally, the quality assurance department runs rigorous regression test suites on each new pass of the operating system, and reports any bugs. It then restores the state of the new process (again this is …

This means that if a system has two IDE controllers there will be entries for the IDE subsystem at indices at 3 and 22 in the blk_dev and blkdevs vectors. When someone detects a bug it reports it to the community and they release a patch as soon as possible …

Its latest releases often inspire the other Linux distributions to adopt new features and make changes. By then, much of the GNU operating system had been completed, with the notable exception of a kernel (i.e., the core of the operating system). The entire Linux kernel was written from scratch …